Question

If AB and CD are parallel, find the value of x in degrees?

• A. ${67}^{\circ }$
• B. ${76}^{\circ }$
• C. ${24}^{\circ }$
• D. ${56}^{\circ }$

Answer 1

The correct option is A ${67}^{\circ }$

$\angle ABC=\angle ECD$ [Alternate angles]

From $\Delta ECD$
$\angle ECD+\angle CDE+\angle DEC={180}^{\circ }$
[Angle sum property]
${73}^{\circ }+{40}^{\circ }+\text{x}={180}^{\circ }$
$\text{x}={180}^{\circ }-{113}^{\circ }$
$\text{x}={67}^{\circ }$